Automated fabrication of composite fillers

ABSTRACT

A composite radius filler having a varying cross-sectional shape is pre-conditioned before being pultruded through forming dies. The composite filler radius filler includes a tab ply having a varying width that is laminated onto a supporting, full width base ply.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is related to co-pending U.S. patent application Ser.No. 14/045,195, filed concurrently herewith on Oct. 3, 2013, which isincorporated by reference herein in its entirety.

BACKGROUND INFORMATION

1. Field

The present disclosure generally relates to the fabrication of compositestructures, and deals more particularly with a method and apparatus forautomated fabrication of composite fillers used to fill a cavity betweenassembled composite members.

2. Background

Assembled composite structures sometimes contain cavities that must befilled in order to maximize the strength and/or rigidity of thestructure. For example, two or more composite members with radiusededges may be assembled together such that their adjacent radiused edgesform a radiused cavity. In order to fill the cavity and strengthen thestructure, a pre-formed radius filler is placed in the cavity and bondedto the members.

Fillers, including radiused fillers used in primary aircraft structuressuch as I-beams and spars, must have tight dimensional specificationsand a high level of both geometric accuracy and compaction in order tomaximize structural strength and avoid resin pooling or the developmentof voids during part cure. Radius fillers may be fabricated by hand,however this production technique is time consuming, labor intensive andmay yield radius fillers that are inconsistent, and/or do not meetrequired specifications.

Automated machines have been proposed for producing radius fillers usinga pultrusion process in which prepreg unidirectional tape iscontinuously pulled through one or more forming dies which form the tapeto the desired cross-sectional radius filler profile. However, theseautomated radius filler machines are not currently capable of producingradius fillers to stringent specifications for peak definition, even plytransitions, symmetry and the absence of loose fibers. Thesedeficiencies are caused, in part, by inadequate pre-conditioning and/orpoor forming die design.

Further problems may be encountered during automated pultrusion ofvariable radius fillers which have cross-sectional profiles that varyalong their length. A pultruded varying cross sectional profile requiresthe use of composite tape having a width that changes at transitionpoints forming “tabs” along one edge of the tape. Although a portion ofthe width of the tape is held in tension during the pultrusion process,the remaining portion containing the tabs is not tensioned, and thus“droops”. The inability to tension and integrate the tabs into thefiller leads to uneven ply transitions and fiber distortions created bythe interaction of the leading edge of the tabs with forming diesurfaces, both of which may affect radius filler quality. Additionally,the existence of tabs along the edge of the radius filler results inasymmetry which create problems when installed.

Accordingly, there is a need for a method and apparatus for producingcomposite radius fillers for high-performance applications that improvepart-to-part uniformity and consistency. There is also a need for amethod and apparatus to improve the surface finish, dimensions, crosssectional profile and integration of tabs in variable composite radiusfillers.

SUMMARY

The disclosed embodiments provide a method and apparatus of producingcomposite radius fillers suitable for use in high-performance compositestructures. The radius fillers are produced using a continuouspultrusion process in which prepreg composite tape is pulled through oneor more forming dies. Radius fillers can be reliably produced havingconsistent cross-sectional profiles with better dimensional control,good quality compaction, and smooth surface finishes. Improved radiusfiller quality is achieved by pre-conditioning the prepreg tape beforeit enters the forming dies.

According to one disclosed embodiment, apparatus is provided for makinga composite filler having a desired cross-section. The apparatuscomprises at least a first prepreg tape feed for feeding a firstcomposite prepreg tape, at least one forming die through which thecomposite prepreg tape may be drawn into the desired cross-section. Theapparatus also includes a prepreg tape pre-conditioning section forpre-conditioning the prepreg tape. The prepreg tape pre-conditioningsection includes a prepreg tape former, and a prepreg tape lead-in dielocated between the preformer and the forming die.

According to another disclosed embodiment, apparatus is provided forpultrusion of a composite radius filler having a cross-section thatvaries along its length. A first tape feed feeds a first compositeprepreg tape ply that includes at least first and second widths formingat least one tab therebetween. A second tape feed feeds a secondcomposite prepreg base ply, and a laminator laminates the tab ply andthe base ply together. A pre-forming section is provided for preformingthe laminated tab and base plies. A forming section forms the pre-formedtab and base plies into cross-sections of differing shapes along thelength of the radius filler.

According to a further disclosed embodiment, a method is provided ofmaking a composite radius filler. A base ply is provided by feedingcomposite prepreg tape having a substantially constant width, and a tabply is provided by feeding composite prepreg tape having a varyingwidth. The base and tab plies are laminated together and then drawnthrough at least first and second forming dies to form differentcross-sectional shapes of the radius filler.

The tape pre-conditioning is achieved using a peak former, a preformerand a pre-forming lead in die, each of which may be fabricated using awear resistant, low friction material. The peak former, preformer andpre-forming lead in die gradually pre-form the tape into across-sectional shape that is a rough approximation of the final desiredradius filler cross-section, thereby reducing the possibility of fibersbeing torn from the tape during pultrusion through the forming dies.These improvements lead to better consolidation of the radius filler andan improvement in filler cross-sectional geometry, including improvedpeak definition, improved symmetry, and improved overall profile.

The peak former includes a V former and inverted V former shapedpreformer that forces the apex to form the peak. The peak former islocated between the heater box and the triangular preformer. Thetriangular preformer includes a tapered conical opening that graduallytransitions into an oversize radius groove, into which prepreg tape ispultruded through. The triangular preformer is located between the peakformer and the pre-forming lead in die. The pre-forming lead in dieincludes an upper die body, a lower die body, and a die insert mountedon the upper die body. The die insert has a radiused front leading edgethat helps gradually transition the prepreg tape material into the leadin die. The lower die body contacts the upper die insert forming thebase of the radius filler. When in contact with each other, the dieinsert and lower die body create an aperture through which the compositetape is pulled to form it in a cross-section that is slightly largerthan the final desired cross-section. The pre-forming lead in die islocated between the triangular preformer and the first forming die.

The features, functions, and advantages can be achieved independently invarious embodiments of the present disclosure or may be combined in yetother embodiments in which further details can be seen with reference tothe following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features believed characteristic of the illustrativeembodiments are set forth in the appended claims. The illustrativeembodiments, however, as well as a preferred mode of use, furtherobjectives and advantages thereof, will best be understood by referenceto the following detailed description of an illustrative embodiment ofthe present disclosure when read in conjunction with the accompanyingdrawings, wherein:

FIG. 1 is an illustration of an end view of a composite I-beam employinga radius filler produced in accordance with the disclosed embodiments.

FIG. 2 is an illustration of an exploded, perspective view of the I-beamshown in FIG. 1.

FIG. 3 is an illustration of a perspective view of a portion of theI-beam shown in FIG. 1, a radius filler of varying cross-section aboutto be placed in a joint in the I-beam.

FIG. 4 is an illustration of a combined schematic and diagrammatic viewof apparatus for producing a composite radius filler.

FIG. 5 is an illustration of a diagrammatic view of a portion of theapparatus shown in FIG. 4, better showing lamination of a tab ply onto abase ply.

FIG. 6 is an illustration of a cross-sectional view taken along the lineFIG. 6-6 in FIG. 5.

FIG. 7 is an illustration of a plan view taken in the direction shown asFIG. 7 in FIG. 6

FIG. 8 is an illustration of an isometric view of a peak-former.

FIG. 9 is an illustration a front view of the peak-former shown in FIG.8.

FIG. 10 is an illustration of a rear view of the peak-former.

FIG. 11 is an illustration of the right side of the peak-former.

FIG. 12 is an illustration of a perspective view of a preformer.

FIG. 13 is an illustration of the upstream end of the preformer.

FIG. 14 is an illustration of the exiting end of the preformer.

FIG. 15 is an illustration of a bottom view of the preformer.

FIG. 16 is an illustration of a diagrammatic view of the profile of thelaminate radius filler after passing through the preformer shown inFIGS. 12-14, the outline of the radius filler being indicated by abroken line.

FIG. 17 is illustration of a perspective view of a pre-forming lead indie which forms part of apparatus shown in FIG. 4.

FIG. 18 is an illustration similar to FIG. 17, but showing the componentparts of the pre-forming lead in die exploded.

FIG. 19 is illustration of a perspective view of the front of the upperdie insert of the pre-forming lead in die.

FIG. 20 is illustration of a perspective view of the rear of the upperdie insert.

FIG. 21 is an illustration of an elevational view better showing thefront of the die opening in the pre-forming lead in die.

FIG. 22 is an illustration of an elevational view better showing therear of the die opening of the pre-forming lead in die.

FIG. 23 is an illustration of a schematic side view of one of theforming dies shown in FIG. 4.

FIG. 24 is an illustration of an isometric view of the forming die shownin FIG. 23.

FIG. 25 is a flow diagram showing the overall steps of a method ofmaking a composite radius filler according to the disclosed embodiments.

FIG. 26 is an illustration of a flow diagram of aircraft production andservice methodology.

FIG. 27 is an illustration of a block diagram of an aircraft.

DETAILED DESCRIPTION

The disclosed embodiments relate to a method and apparatus for producinghigh-performance composite fillers, sometimes referred to hereinafter as“radius fillers”, The radius fillers may be used to strengthen primarycomposite structures and assemblies, such as the composite laminateI-beam 30 shown in FIGS. 1, 2 and 3. The I-beam 30 comprises upper andlower composite laminate caps 34 joined by a web 32. The I-beam 30 maybe produced by joining a pair of C-shaped, composite laminate members 36having outwardly turned flanges 38, each of which transitions to the web32 through a radiused corner 46.

The area between adjacent radius corners 46 and a cap 34 forms a void 40that may be filled by a radius filler 42 produced in accordance with thedisclosed embodiments described below. In the illustrated embodiment,the gauge or thickness of the C-shaped members 36 varies along itslength, consequently, different sections 38 a, 38 b, 38 c of the flanges38 have differing thicknesses. Due to these varying thicknesses, theradius of the corners 46 also varies.

The radius filler 42 may comprise, without limitation, prepreg tape,such as carbon fiber epoxy, that is folded, formed and compacted intothe desired cross-sectional profile, continuously along the length ofthe radius filler 42. In the illustrated embodiment, due to the presenceof the radiused corners 46, the radius filler 42 possesses matchinginside radii 44 and may therefore be referred to as a “radius filler”,however it is to be understood that the disclosed embodiments may beemployed to produce fillers having a wide variety of othercross-sectional shapes. The cross-sectional profile of the radius filler42 may vary along its length to match the changing gauge of the C-shapedmembers 36. Thus, in the example shown in FIG. 3, the radius fillercomprises three sections 42 a, 42 b, 42 c which respectively havecross-sectional profiles that match the shape of the groove or void 40present between the flanges 38 and the caps 34.

The radius filler 42 may be fabricated using a pultrusion apparatusgenerally illustrated in FIG. 4. Broadly, first and second prepreg tapefeeds 50, 84 supply prepreg tape 48 which form a tab ply 48 a and a baseply 82 that are laminated together, pre-conditioned, aligned and thenpulled by a puller (not shown) continuously through a set of formingdies 124, all mounted on a machine frame 130, before exiting theapparatus at 128, as a continuous radius filler 42. A cutter (not shown)cuts the continuous radius filler 42 to the desired length.

More particularly, composite prepreg tape 48 drawn from the first tapefeed 50 is delivered through a splice detector 52 and then through analignment station 54 that transversely aligns the tape 48. The width ofthe tape 48 and its transverse alignment is shown at 56 after passingthrough the alignment station 54. The tape 48 then passes through a webalignment sensor 58 which senses and verifies alignment of the tape 48.The tape 48 is looped around a web tension transducer 60 which sensesthe tension in the tape 48 before being fed to a tape slitter 62. Thetape slitter 62 may comprise, for example and without limitation, anultrasonic knife which continuously cuts the tape to one or more desiredwidths, depending upon the varying cross-sectional profile of the radiusfiller 42.

As the tape slitter 62 cuts the tape 48 to various widths, tabs 93, 95(see FIG. 7) are formed along the outer edge of the tape 48 which formtransitions between differing sections of the tape 48 that havedifferent widths. The tape 48 having the desired tape profile cut by theslitter 62 forms a tab ply 48 a (discussed later in more detail) andshown at 66. The portion of the tape 48 that is cut away by the tapeslitter 62 is fed as a tape scrap 72 to a scrap take-up reel 74.Additionally, a backing paper 76 may be drawn off of the tab ply 48 aand onto a paper take-up spool 78.

The tab ply 48 a having the desired cut width passes across a pair ofweb tension transducers 68, 70 and across a web width sensor 80 whichsenses the width, and thus the profile, of the tab ply 48 a. A secondtape feed 84, which may comprise a spool of composite prepreg tape,delivers tape forming a base ply 82 of constant width over a roll 92.Backing paper 88 from the base ply 82 is passed over a roll 90 and isdrawn onto the paper take-up spool 78. The tab ply 48 a along with thebase ply 82, are fed in stacked relationship, as shown at 94 into a nip105 (FIG. 5) between two laminating rollers 96. The laminating rollers96 press and thereby laminate the tab ply 48 a and base ply 82 together.The laminated plies 48 a and 82 then pass through a pair of corrugatedrollers 98 which form corrugations in the laminate, as shown at 100. Thecorrugated laminate passes through a heater box 102 which heats andsoftens the laminate to a suitable forming temperature.

The corrugated laminate is then pulled through a pre-conditioningsection 115, comprising a peak former 104 mounted on a support 106, apreformer 110 mounted on a base 112, and a pre-forming lead in die 116.The pre-conditioning section 115 functions to both pre-align andpre-form the heated laminate (i.e. tab ply 48 a and base ply 82), suchthat the laminate is pre-formed into a profile shape that issubstantially similar to, but larger in size than the finished radiusfiller 42.

The pre-conditioning section 115 reduces the amount of forming work thatmust be later performed by forming dies 124 (discussed below) in orderto create the final radius filler profile, and leads to improvedconsolidation of the radius filler 42, as well as an improvement in theradius filler cross-sectional geometry, including peak definition, peaksymmetry and overall profile. Moreover, pre-conditioning and alignmentof the heated laminate prior to forming reduces the possibility thatreinforcing fibers in the laminate will be torn from the surface of theradius filler 42 when the laminate is being pultruded through theforming dies 124. It should be noted here that while a singlepre-forming lead in die 116 is employed to pre-form the laminate priorto being drawn into the forming section 122, in some embodiments, it maybe necessary or desirable to employ a second pre-forming lead in die(not shown) downstream of the forming section 122 in order to furtherpre-form the laminate and assist in maintaining alignment of the radiusfiller 42 as it is being drawn through the dies 124.

The peak former 104 reduces the width, rolls the edges upward and towardcenterline and forms a peak 125 in the corrugated laminate, as shown at100. The laminate then is drawn through the tape preformer 110 which ismounted on a base 112. The tape preformer 110 collimates the laminateinto the general shape of the radius filler 42, which in the illustratedexample is a generally triangular shape, as shown at 114. Next, thecollimated laminate is pulled through a pre-forming lead in die 116which forms the laminate into a cross-sectional profile that hassubstantially the same shape as, but is larger in dimension than thefinished radius filler 42. After passing through the pre-forming lead indie 116, the nearly-formed-to-shape laminate is pultruded through theforming section 122 which comprises one or more forming dies 124. In theillustrated example, eleven forming dies 124 are employed, however moreor less than eleven forming dies 124 may be employed, depending upon theparticular radius filler 42 being formed.

In the case of radius fillers 42 having cross-sectional shapes that varyalong their lengths, the forming dies 124 have differently shapedopenings and are selectively engaged with the pre-formed laminate by acorresponding pneumatic or electrical actuator 118 which opens andcloses the forming die 124. As previously mentioned, although not shownin FIG. 4, after exiting 128 the forming section 122, the radius filler42 is cut to a desired length by a cutter. The peak former 104,preformer 110 and pre-forming lead in die 116 remain engaged with thelaminate throughout pultrusion of the radius filler through the formingdies 124 in the forming section 122.

Attention is now directed to FIGS. 5, 6 and 7 which diagrammaticallyillustrate a technique for improving the quality of the finished radiusfiller 42 by laminating the variable width tab ply 48 a onto theconstant width base ply 82. Lamination of the tab ply 48 a onto theunderlying base ply 82 better integrates the tabs 93, 95 into the radiusfiller 42, eliminating surface discontinuities and reducing fibertear-out at transitions between variable cross-sections on the radiusfiller 42. As previously discussed, the tab ply 48 a and the base ply 82are fed together into a nip 105 between a pair of laminating rollers 96which may be closed to compress and thereby laminate the tab and baseplies 48 a, 82 together. The inside edge 85 of the tab ply 48 a may beoffset relative to the inside edge 87 of the base ply 82. In theillustrated embodiment, the inside edge 85 of the tab ply 48 a is offseta distance D₂ from the inner edge 96 a of the lamination rollers 96 thatis greater than the offset distance D₁, thereby bringing the centerlineof the tab ply 48 a closer to the centerline of the base ply 82. Inother embodiments however, depending on application, D₂ may be equal toor less than D₁.

The variable width tab ply 48 a is placed on the constant width base ply82 such that the constant width base ply supports each tab 93, 95 of thetab ply 48 a and holds these tabs 93, 95 in tension throughout theforming process. In other words, the base ply 82 acts as a carrier thatsupports those portions of the tab ply 48 a, i.e. the tabs 93, 95, thatare not held in tension. Because the base ply 82 acts as an underlyingsupporting carrier, drooping or sagging of the tabs 93, 95 which leadsto uneven surfaces at transitions between different radius fillercross-sections is eliminated. Also, because the edges of the tabs 93, 95are no longer exposed when travelling through the forming dies 123 inthe forming section 122, fiber tear-out at cross-section transitions isgreatly reduced.

FIGS. 8-11 illustrate additional details of the peak former 104. Thepeak former 104 broadly comprises a V-former 134 and an invertedV-former 136 arranged back-to-back such that the laminate first engagesand is formed by the inverted V-former 136 and is then formed by theV-former 134. The inverted V-former 136 includes an inverted V or apex142 that forms the peak 125 (see FIG. 3) into the laminate. The V-former134 includes a V-shaped recess 140 that rolls the edges of thecorrugated laminate up and toward centerline to ensure that they are inthe interior of the finished radius filler 42 and are not left exposedon the outside surface. The inverted V-former 136 and the V-former 134may each include slots 138 which receive fasteners (not shown) formounting the peak former assembly 104 on a support 106 (FIG. 3) in sucha way that the alignment between the two components may be adjusted.Each of the V-former 134 and the inverted V-former 136 may be fabricatedfrom a low friction, wear resistant material such as, for example andwithout limitation, an ultra high molecular weight polyethylene(UHMWPE).

Referring now to FIGS. 12-15, the preformer 110 comprises a body 148having a generally conical, tapered inlet opening 150. The tapered inletopening 150 has a generally arcuate outer periphery and transitions intoan over-sized radiused pre-forming groove 152 in one face 155 thereof.The pre-forming groove 152 has a cross section that generallyapproximates the final cross section of the radius filler. Thepre-forming groove 152 is downstream of the tapered inlet opening 150and, in the illustrated embodiments, has a generally triangularcross-sectional shape, although other cross sectional shapes arepossible, depending on the geometry of the filler 42. The body 148 maybe fabricated from a low friction, wear resistant material such as, forexample and without limitation, an ultra high molecular weightpolyethylene (UHMWPE). The body 148 is adapted to be mounted byfasteners (not shown) on a flat surface of the base 112 (see FIG. 3).The tapered inlet opening 150 collimates the laminate into thepre-forming groove 152 which pre-forms the laminate into across-sectional shape that is generally triangular

FIG. 16 diagrammatically illustrates a radius filler 42 after havingbeen pulled through the preformer 110 shown in FIGS. 12-14. The tab ply48 a, and the base ply 82 can be seen to have been compressed to formradius sides 137, and a substantially flat base 139 of the radius filler42 generally matching the profile (shown in broken lines) of the radiusfiller 42. The peak 101 into which the laminated tab ply 48 a and baseply 82 previously formed by the peak former 104 can be seen to havefilled the apex area 141 of the radius filler 42.

FIGS. 17-22 illustrate the pre-forming lead in die 156 in more detail.The pre-forming lead in die 116 broadly comprises an upper, main diebody 158, a lower die 160, an upper die insert 162, secured together byany suitable means, such as fasteners (not shown). Each of the upper diebody 158, lower die 160 and the die insert 162 may be fabricated from alow friction, wear resistant material such as, for example and withoutlimitation, an ultra high molecular weight polyethylene (UHMWPE).

The upper die body 158 includes a pair of spaced apart, forwardlyprojecting locator supports 165 for locating the die insert 162 and forcontaining the composite laminate laterally as it is being pulledthrough the pre-forming lead in die 116. The lower die 160 includes asubstantially flat die face 161 having a radiused leading edge 169.

As best seen in FIGS. 19-22, the die insert 162 includes a radiusedleading edge 168 which tapers to a forming passageway 166 defined by apair of radiused die faces 170, 172. Thus, the die faces 161, 170, 172form a die inlet opening 164 that is radiused or tapered at its leadingedges 161, 169 but transitions into a cross-sectional profile(passageway 166) that is substantially identical to, but is slightlylarger in dimension than that of the final cross-sectional profile ofthe radius filler 42. The die forming passageway 166 has a length L thatis sufficient to allow enough contact between the laminate and thepre-forming lead in die 116 such that the laminate is substantiallyfully formed into the final pre-form radius filler cross-sectionalprofile upon exit from the preforming die 116, before entering one ormore of the forming dies 124, where the radius filler 42 is formed toits final profile shape and dimensions. Passageway 166 may be tapered orof constant cross-section, depending on the particular filler 44 beingproduced.

Attention is now directed to FIGS. 23 and 24 which illustrate one of thedies 124 mounted on the machine frame 130. The die 124 broadly comprisesan upper roller die assembly 178 and a lower roller die assembly 180between which the pre-formed composite laminate is formed into thedesired radius filler 42. The upper and lower roller die assemblies 178,180 are mounted on the machine frame in indexed relationship to eachother to form a die opening therebetween 187 having a desiredorientation relative to the movement of the laminate through the die124. The upper roller die assembly 178 is mounted on a guide rail 194for movement 196 toward and away the lower roller die assembly 180,between an open, standby position (shown in FIG. 23) and an operativeforming position (shown in FIG. 24). The guide rail 194 is secured tothe machine frame 130 by any suitable means. The lower roller dieassembly 180 is stationarily fixed to the machine frame 130. An actuator118 is coupled with and controls the movement 196 of the upper dieassembly 178 along the guide rail 194.

Referring particularly to FIG. 24, the upper roller die assembly 178includes an upper roller die 182 that is journaled for rotation on anupper mount 186. Similarly, the lower roller die assembly 180 includes alower roller die 188 journaled for rotation on a lower mount 190. Theupper roller die 182 includes a grooved die face 184 having radii forforming a radiused portion of the radius filler 42, and the lower rollerdie 188 includes a flat die face 192 for forming the remaining, flatportion of the radius filler 42. Together, the grooved die face 184 andthe flat die face 192 form a die opening 187 having a shape thatsubstantially matches that cross-sectional shape or profile of thefinished radius filler 42.

Attention is now directed to FIG. 25 which broadly illustrates theoverall steps of a method of producing a composite filler radius filler42, such as a radius filler that varies in cross-sectional profile alongits length. Beginning at 198, a base ply 82 is provided, such as byfeeding prepreg composite tape having a substantially constant width. At200, tab ply 48 a is provided, as by feeding prepreg composite tapehaving a varying width. At step 202, the tab ply 48 a and the base ply82 are laminated together, as for example by feeding the two plies intoa nip 105 between two lamination rollers 96. At 204, the laminated plies48 a, are pre-conditioned and aligned in preparation for forming. Thepre-conditioning and aligning may be accomplished by pulling thelaminated plies through a peak former 104, tape preformer 110 and apre-forming lead in die 116. Finally, at step 206, the pre-conditionedand aligned laminated plies are pulled through various forming dies 124in order to form two or more different sections 42 a, 42 b of the radiusfiller 42 into differing cross-sectional profiles.

Embodiments of the disclosure may find use in a variety of potentialapplications, particularly in the transportation industry, including forexample, aerospace, marine, automotive applications and otherapplication where cavities that must be filled exist between compositemembers. Thus, referring now to FIGS. 26 and 27, embodiments of thedisclosure may be used in the context of an aircraft manufacturing andservice method 208 as shown in FIG. 26 and an aircraft airframe 226 asshown in FIG. 27. Aircraft applications of the disclosed embodiments mayinclude, for example, without limitation, radius fillers used to fillradiused cavities in composite beams, spars and other stiffeners. Duringpre-production, exemplary method 208 may include specification anddesign 212 of the aircraft 210 and material procurement 214. Duringproduction, component and subassembly manufacturing 216 and systemintegration 218 of the aircraft 210 takes place. Thereafter, theaircraft 210 may go through certification and delivery 220 in order tobe placed in service 222. While in service by a customer, the aircraft210 is scheduled for routine maintenance and service 224, which may alsoinclude modification, reconfiguration, refurbishment, and so on.

Each of the processes of method 208 may be performed or carried out by asystem integrator, a third party, and/or an operator (e.g., a customer).For the purposes of this description, a system integrator may includewithout limitation any number of aircraft manufacturers and major-systemsubcontractors; a third party may include without limitation any numberof vendors, subcontractors, and suppliers; and an operator may be anairline, leasing company, military entity, service organization, and soon.

As shown in FIG. 27, the aircraft 210 produced by exemplary method 208may include an airframe 226 with a plurality of systems 228 and aninterior 230. Examples of high-level systems 228 include one or more ofa propulsion system 232, an electrical system 234, a hydraulic system236 and an environmental system 238. Any number of other systems may beincluded. The disclosed method and apparatus may be employed to produceradius fillers used to fill radiused cavities in composite assembliesused in the airframe 226. Although an aerospace example is shown, theprinciples of the disclosure may be applied to other industries, such asthe marine and automotive industries.

Systems and methods embodied herein may be employed during any one ormore of the stages of the production and service method 208. Forexample, components or subassemblies corresponding to production process216 may be fabricated or manufactured in a manner similar to componentsor subassemblies produced while the aircraft 210 is in service. Also,one or more apparatus embodiments, method embodiments, or a combinationthereof may be utilized during the production stages 216 and 218, forexample, by substantially expediting assembly of or reducing the cost ofan aircraft 210. Similarly, one or more of apparatus embodiments, methodembodiments, or a combination thereof may be utilized while the aircraft210 is in service, for example and without limitation, to maintenanceand service 224.

As used herein, the phrase “at least one of”, when used with a list ofitems, means different combinations of one or more of the listed itemsmay be used and only one of each item in the list may be needed. Forexample, “at least one of item A, item B, and item C” may include,without limitation, item A, item A and item B, or item B. This examplealso may include item A, item B, and item C or item B and item C. Theitem may be a particular object, thing, or a category. In other words,at least one of means any combination items and number of items may beused from the list but not all of the items in the list are required.

The description of the different illustrative embodiments has beenpresented for purposes of illustration and description, and is notintended to be exhaustive or limited to the embodiments in the formdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art. Further, different illustrativeembodiments may provide different advantages as compared to otherillustrative embodiments. The embodiment or embodiments selected arechosen and described in order to best explain the principles of theembodiments, the practical application, and to enable others of ordinaryskill in the art to understand the disclosure for various embodimentswith various modifications as are suited to the particular usecontemplated.

What is claimed is:
 1. Apparatus for pultrusion of a composite radiusfiller having a cross section that varies along its length, comprising:a first tape feed for feeding a first composite prepreg tab ply, whereinthe tab ply includes at least first and second widths forming at leastone tab therebetween; a second tape feed for feeding a second compositeprepreg base ply; a laminator for laminating together the tab ply andthe base ply; a pre-forming section for pre-forming the laminated taband base plies, wherein the preformer includes a tapered conical openingthat gradually transitions into a radiused groove having a firstcross-section generally approximating a second cross section of thecomposite radius filler, wherein the pre-forming section furthercomprises: a main die body; a second die connected to and below the maindie with respect to gravity; and a die insert connected to the main diebody; and a forming section for forming the pre-formed tab and baseplies into cross-sections of differing shapes along the length of theradius filler.
 2. The apparatus of claim 1, wherein: the laminatorincludes a pair of rollers having a nip therebetween into which the tabply and the base ply are fed.
 3. The apparatus of claim 2, wherein thesecond tape feed includes a take-up spool capable of taking up a backingon the base ply as the base ply is being fed to the laminator.
 4. Theapparatus of claim 1, wherein the pre-forming section includes a peakformer for forming a peak in the laminated tab ply and base ply.
 5. Theapparatus of claim 4, wherein the pre-forming section includes apreformer for rolling edges of the laminated tab ply and base ply towarda centerline of the base ply after the peak has been formed in thelaminated tab ply and base ply.
 6. The apparatus of claim 5, wherein theradiused groove is oversized.
 7. The apparatus of claim 1, wherein thefirst and second tape feeds are arranged to offset the tab ply relativeto the base ply such that the base ply is disposed beneath and supportsthe tab.
 8. The apparatus of claim 1, wherein the main die body includesa pair of spaced apart, forwardly projecting locator supports forlocating the die insert and for containing the composite radius fillerlaterally as the composite radius filler is pulled through thepre-forming section.
 9. The apparatus of claim 8, wherein the second dieincludes a substantially flat die face having a radiused leading edge.10. The apparatus of claim 9, wherein the radiused leading edge istapered and transitions into a cross-sectional profile that issubstantially identical to, but is slightly larger in profile, of thecomposite radius filler.
 11. The apparatus of claim 1, wherein theforming section comprises: a first die roller assembly mounted on aframe of the apparatus; and a second die roller assembly mounted on theframe below the first die roller assembly relative to gravity and in anindexed relationship with the first die roller assembly, wherein thecomposite radius filler is formed into a desired shape between the firstdie roller assembly and the second die roller assembly.
 12. Theapparatus of claim 11, wherein the first die roller assembly is mountedon a guide rail secured the frame, the guide rail configured to movetoward and away from the second die roller assembly.
 13. The apparatusof claim 12, wherein the second die roller assembly is stationarilyfixed to the frame.
 14. The apparatus of claim 13 further comprising: anactuator coupled with the first die roller assembly and configured tocontrol movement of the first guide rail assembly along the guide rail,wherein the first die roller assembly includes a grooved die face havingradii for forming a radiused portion of the composite radius filler, andwherein the second die roller assembly includes a flat die face forforming a remaining flat portion of the composite radius filler.